360 LA getting oil in #3 cylinder.

Take a good look fellas; OP says that's oil and water.
I want to agree............
20230302_230916-jpg.jpg

Especially since the same piston elsewhere looks like this:
20230302_230919-jpg.jpg
And the valves in that chamber like this
20230302_230812-jpg.jpg
I've seen a lotta detonation evidence in my vocation, but never one like this..............